Hughs Autoformer

To repeat much of what has been said in different terms, a correct 30 amp service will give you 30 amps at 120 volts, or 3,600 watts. If drawing 30 amps pulls the power feed down to 100 volts, the most you will get from that connection is 3,000 watts. You have the option of using an autoformer to convert that 100 volts at 30 amps to 120 volts at 25 amps (ignoring transformer losses which are pretty minimal). The example power-impaired campground gives you at most 3,000 watts. With the autoformer you can decide what you want the voltage-current relationship to be. One camper with an autoformer could very well be using less power than another camper not using an autoformer. It would take measuring everybody's power usage to decide exactly who is stealing from who.